[Change of ambulatory blood pressure-related parameters for different levels of renal function in resistant hypertension]

To explore the predictive values of ambulatory blood pressure-related parameters for moderate renal impairment in resistant hypertension (RH).

The clinical data were retrospectively analyzed for 401 hospitalized patients with hypertension at our hospital from October 2010 to October 2013. They were divided into RH (n = 263) and non-RH (n = 138). The modified estimating equation of glomerular filtration rate (GFR) for Chinese patients was used to assess renal functions. The standardization of moderate renal impairment was when GFR below 60 ml · min⁻¹ · 1.73 m⁻². The ambulatory blood pressure-related parameters were obtained by 24 h ambulatory blood pressure monitoring. The important prediction of these parameters for moderate renal impairment was accessed by receiver operating characteristic (ROC) curve. And the related risk factors for renal function impairment were tested by multiple stepwise Logistic regression analysis.

Ambulatory arterial stiffness index (AASI), 24 h mean pulse pressure (24 hPP), sleeptime relative systolic blood pressure (SBP) decline and 24 h systolic blood pressure (24 hSBP) had important predictive values for moderate renal impairment in RH. GFR was significantly lower in those with AASI ≥ 0.485, 24 hPP ≥ 47.5 mmHg, sleeptime relative SBP decline ≤ -1.75% and 24 hSBP ≥ 130.5 mmHg (P < 0.05). Area under curve of ROC curve of AASI, 24 hPP, sleeptime relative SBP decline and 24 hSBP were 0.804, 0.644, 0.602 and 0.623 respectively. Multiple Logistic regression analysis showed that AASI (OR 1 268.5, P = 0.000), low density lipoprotein (OR 0.7, P = 0.01) and sleeptime relative SBP decline (OR 1.3, P = 0.01) were independent risk factors for GFR < 60 ml · min⁻¹ · 1.73 m⁻² in RH.

AASI, 24 hPP, sleeptime relative SBP decline and 24 hSBP are the most significant ambulatory blood pressure-related parameters in predicting renal impairment in resistant hypertension.